Fluorescent lamps, and all other gas discharge lamps, require a ballast to provide a high starting voltage to initiate the lamp and then use current limiting to safely sustain the discharge. Lamp manufacturers specify the lamp current, starting voltage, current crest factor, and other parameters for rated lamp life and output lumens. The American National Standards Institute (ANSI) publishes lamp input specifications for all ANSI type lamps. There are standard output (SO), high output (HO), and very high output (VHO) lamp tubes, each use different connectors. A typical 40 W 48″ tube is supposed to run at 0.43 A., start at 400V-650V and have about a 93V working voltage. HO's operate at 1.0 A. VHO's operate at 1.5 A, e.g., 109 W.
Conventional ballasts use magnetic transformers operating at line frequency, and therefore are prone to buzzing and humming noises. Newer ballasts are electronic, do not use transformers, and can be absolutely mechanically silent. Magnetic ballasts are only crude AC current regulators, they make noise, do not tolerate temperature changes well, and often produce flickering. Newer electronic ballasts are now replacing the older types, and these can even correct the power factor, e.g., current is drawn over the entire AC cycle, not just the crests.
Many prior art patents in the United States discuss the desirability of making ballasts simple enough for ordinary consumers to change, but none has resulted in any widespread distribution of such lamp systems. The probable reason is each lamp type requires its own special ballast, and ballasts are very cost sensitive in the market. What is needed is a simple-to-install modular electronic ballast that can adapt itself to the job presented by reading power signatures from the lamps themselves or from data embedded for this purpose in the fixtures they plug into.